High voltage high side transistor driver

ABSTRACT

A high side transistor driver includes a sender module that generates a power input signal. A converter module receives the power input signal and generates an output signal that has a higher voltage than the power input signal. A receiver module receives the output signal and the power input signal and transitions a transistor between ON and OFF states based on the output signal and the power input signal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/720,866, filed on Sep. 27, 2005. The disclosure of the aboveapplication is incorporated herein by reference in its entirety.

FIELD

The present disclosure relates to high-side transistor drivers, and moreparticularly to a high voltage, high-side transistor driver.

BACKGROUND

High side transistor drivers are used to drive a high side transistorthat is connected to a positive supply and is floating (i.e., that isnot ground-referenced). The transistor may be a MOSFET (metal oxidesemiconductor field effect transistor) or an IGBT (insulated gatebipolar transistor). High side transistors may require a voltagetranslation from a level shifting device such as a high voltage levelshifter. Floating transistors such as the high side transistors may bedifficult to turn ON and OFF quickly.

Referring now to FIG. 1, an exemplary transistor driver circuit 10 isshown. The transistor driver circuit 10 includes a high side transistor12 and a low side transistor 14. A high side transistor driver 16 isconnected to a gate 18 of the high side transistor 12 and selectivelyturns the high side transistor 12 ON and OFF. A low side transistordriver 20 is connected to a gate 22 of the low side transistor 14 andselectively turns the low side transistor 14 ON and OFF. The high sidetransistor driver 16 and the low side transistor driver 20 may beintegrated in a transistor driver module 24. For example, the drivers 16and 20 turn the transistors 12 and 14 ON and OFF to vary current and/orvoltage to an output node 26 according to input signals 28 and 30.

Referring now to FIG. 2, an exemplary arrangement of the high sidetransistor 12 and the high side transistor driver 16 is shown in moredetail. The input signal 28 is input to the high side transistor driver16 through a high voltage level shifter 40 and an inverter 42. Forexample, the high voltage level shifter 40 may include a high voltagetransistor. Although only a single high voltage transistor is shown,additional high voltage transistors may be necessary to implement thehigh voltage level shifter 40. Typically, integration of multiple highvoltage transistors with other low voltage transistors (not shown) onthe same die may be difficult.

Further, for certain applications (e.g., such as fluorescent ballastdrivers), voltage stress of more than 600 volts may be applied to thehigh voltage transistors. Circuitry of the high side transistor driver16 needs to be able to float above ground by a similar voltage level. Asa result, specialty semiconductor processes, such as thick oxide SOI(silicon-on-insulator) processes, may be used. However, because of thelarge junction capacitances of high voltage transistors, the resultingcircuit is typically quite slow. For example, some ballast drivers thatimplement the high side transistor driver 16 as described in FIG. 2 mayoperate at a maximum of 50 kHz.

SUMMARY

A high side transistor driver comprises A sender module that generates apower input signal. A converter module receives the power input signaland generates an output signal that has a higher voltage than the powerinput signal. A receiver module receives the output signal and the powerinput signal and transitions a transistor between ON and OFF statesbased on the output signal and the power input signal.

In other features of the invention, the converter module includes atransformer that receives the power input signal. The converter moduleincludes a rectifier that communicates with the transformer andgenerates the output signal. The power input signal includes an embeddedsignal that indicates a desired state of the transistor. The receivermodule detects the embedded signal and transitions the transistor basedon the embedded signal. The power input signal has a first frequency anda second frequency that is lower than the first frequency, wherein thesecond frequency indicates the embedded signal.

In other features of the invention, the high side transistor drivercomprises a second receiver module, wherein the receiver module islocated on a high voltage side of the high side transistor driver andthe second receiver module is located on a low voltage side of the highside transistor driver. The receiver module generates a status signaland the second receiver module receives the status signal. The statussignal is indicative of at least one of a short circuit condition, anover temperature condition, and a polarity of a transformer incommunication with the converter module.

In other features of the invention, an oscillator generates anoscillation signal. A digital state machine generates the power inputsignal in response to the oscillation signal. The high side transistordriver further comprises a digital interpolator.

In other features of the invention, a ballast for a fluorescent lightcomprises the high side transistor driver. The ballast provides currentand/or voltage to the fluorescent light based on the state of thetransistor. A ballast logic module includes the sender module. Theconverter module implements a DC/DC converter and the sender modulesynchronizes the DC/DC converter with the embedded signal. The powerinput signal includes phase encoding and power delivery components.

In other features of the invention, a high side transistor drivercomprises a converter module including a transformer that receives apower input signal and generates an output signal that has a highervoltage than the power input signal. An input module includes atransformer that receives a driver input signal and generates a driversignal in response to the driver input signal, wherein the driver inputsignal includes pulses. A receiver module receives the output signal andthe driver signal and transitions a transistor between ON and OFF statesbased on the output signal and the driver signal. A delay matchingmodule adds a delay to a low side transistor, wherein the delaycorresponds to a delay of the high side transistor driver. The sendermodule generates a time allocation signal that indicates when the secondreceiver module is operable to receive the status signal.

A high side transistor driver comprises sending means for generating apower input signal, converting means for receiving the power inputsignal and generating an output signal that has a higher voltage thanthe power input signal, and receiving means for receiving the outputsignal and the power input signal and for transitioning a transistorbetween ON and OFF states based on the output signal and the power inputsignal.

In other features of the invention, the converting means includes atransformer that receives the power input signal. The converting meansincludes a rectifier that communicates with the transformer andgenerates the output signal. The power input signal includes an embeddedsignal that indicates a desired state of the transistor. The receivingmeans detects the embedded signal and transitions the transistor basedon the embedded signal. The power input signal has a first frequency anda second frequency that is lower than the first frequency, wherein thesecond frequency indicates the embedded signal.

In other features of the invention, the high side transistor driverfurther comprises second receiving means for receiving a status signal,wherein the receiving means is located on a high voltage side of thehigh side transistor driver and the second receiving means is located ona low voltage side of the high side transistor driver. The receivingmeans generates the status signal. The status signal is indicative of atleast one of a short circuit condition, an over temperature condition,and a polarity of a transformer in communication with the convertingmeans.

In other features of the invention, the high side transistor driverfurther comprises oscillating means for generating an oscillation signaland digital state machine means for generating the power input signal inresponse to the oscillation signal. The high side transistor driverfurther comprises digital interpolating means for increasing an outputfrequency resolution.

In other features of the invention, a ballast for a fluorescent lightcomprises the high side transistor driver. The ballast provides currentand/or voltage to the fluorescent light based on the state of thetransistor. The converter module implements a DC/DC converter and thesending means synchronizes the DC/DC converter with the embedded signal.The power input signal includes phase encoding and power deliverycomponents.

In other features of the invention, a high side transistor drivercomprises converting means including a transformer for receiving a powerinput signal and generating an output signal that has a higher voltagethan the power input signal, input means including a transformer forreceiving a driver input signal and generating a driver signal inresponse to the driver input signal, wherein the driver input signalincludes pulses, and receiving means for receiving the output signal andthe driver signal and for transitioning a transistor between ON and OFFstates based on the output signal and the driver signal. The high sidetransistor driver further comprises delay matching means for adding adelay to a low side transistor, wherein the delay corresponds to a delayof the high side transistor driver. The sending means generates a timeallocation signal that indicates when the second receiving means isoperable to receive the status signal.

A method for driving a high side transistor in a circuit comprisesgenerating a power input signal, receiving the power input signal andgenerating an output signal that has a higher voltage than the powerinput signal at a first module, receiving the output signal and thepower input signal at a second module, and transitioning a transistorbetween ON and OFF states based on the output signal and the power inputsignal.

In other features of the invention, the step of receiving the powerinput signal at the first module includes receiving the power inputsignal at a transformer. The power input signal is rectified at thefirst module. The power input signal includes an embedded signal thatindicates a desired state of the transistor. The embedded signal isdetected and the transistor is transitioned based on the embeddedsignal. The power input signal has a first frequency and a secondfrequency that is lower than the first frequency, wherein the secondfrequency indicates the embedded signal.

In other features of the invention, a status signal is generated at thesecond module. The status signal is received at a third module. Thesecond module is located on a high voltage side of the circuit and thethird module is located on a low voltage side of the circuit. The statussignal is indicative of at least one of a short circuit condition, anover temperature condition, and a polarity of a transformer incommunication with the first module.

In other features of the invention, an oscillation signal is generated.The power input signal is generated at a digital state machine inresponse to the oscillation signal. Current and/or voltage is providedto a fluorescent light based on the state of the transistor. The firstmodule includes a DC/DC converter and the DC/DC converter issynchronized with the embedded signal. The method further comprisesadding a delay to a low side transistor, wherein the delay correspondsto a delay of the high side transistor. The method further comprisesgenerating a time allocation signal that indicates when the third moduleis operable to receive the status signal.

Further areas of applicability of the present disclosure will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred embodiment of the disclosure, are intended forpurposes of illustration only and are not intended to limit the scope ofthe disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a schematic of a transistor driver circuit according to theprior art;

FIG. 2 is a schematic of a high side transistor driver including a highvoltage level shifter according to the prior art;

FIG. 3 is a functional block diagram of a high side transistor driveraccording to the present invention;

FIG. 4A is a functional block diagram of a high side transistor driverincluding embedded signaling according to the present invention;

FIG. 4B is a circuit schematic of a converter module that includes an Hbridge driver according to the present invention;

FIG. 4C is a circuit schematic of a converter module that includes acenter tap push pull driver according to the present invention;

FIG. 5 illustrates a power input signal including embedded signalingaccording to the present invention;

FIG. 6 is a functional block diagram of a high side transistor driverincluding reverse signaling according to the present invention;

FIG. 7 is a functional block diagram of a fluorescent ballast thatincludes a high side transistor driver according to the presentinvention;

FIG. 8A is a functional block diagram of a ballast logic moduleaccording to the present invention; and

FIG. 8B is a functional block diagram of a second implementation of theballast logic module according to the present invention.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is in no wayintended to limit the disclosure, its application, or uses. For purposesof clarity, the same reference numbers will be used in the drawings toidentify similar elements. As used herein, the term module, circuitand/or device refers to an Application Specific Integrated Circuit(ASIC), an electronic circuit, a processor (shared, dedicated, or group)and memory that execute one or more software or firmware programs, acombinational logic circuit, and/or other suitable components thatprovide the described functionality. As used herein, the phrase at leastone of A, B, and C should be construed to mean a logical (A or B or C),using a non-exclusive logical or. It should be understood that stepswithin a method may be executed in different order without altering theprinciples of the present disclosure.

The high side transistor driver of the present invention includes atransformer and eliminates the high voltage transistor/transistors usedin the high voltage level shifter as described in FIG. 2. Thetransformer implements high frequency power delivery and, in certainimplementations, embedded signaling.

Referring now to FIG. 3, a high side transistor circuit 50 includes aconverter module 52, an input signal module 54, a receiver module 56,and a high side transistor 58. The converter module 54 receives a powerinput signal at power input nodes 60 and 62. For example, the powerinput signal may be a square wave signal as indicated at 64, althoughother input signals may be used. The converter module 54 may include atransformer 66 and a rectifier 68. The converter module 54 converts thepower input signal to a DC output signal 70 that is output to thereceiver module 56. The converter module 52 implements a high frequency,push-pull DC/DC converter that delivers power from a low side (i.e. thepower input signal 64) to a high side (i.e. the DC output signal 70).For example, the transformer 66 may be sufficiently small to reducemanufacturing costs and space requirements. As such, the transformer 66may require higher frequency operation. The transformer 66 isolates theDC output signal 70 from the power input signal 64.

The input signal module 54 includes a transformer 72 and receives adriver input signal 74 at input nodes 76 and 78. The driver input signal74 may include input pulses (as indicated at 80) or other input signalsthat tend to avoid saturating a core of the transformer 72. The inputsignal module 54 outputs a driver signal 82 to the receiver module 56.The receiver module 56 receives and processes the driver signal 82 andconverts the input pulses 80 to a high or low signal suitable fordriving the high side transistor 58. The converter module 52 providesthe energy required to drive the high side transistor 58 and the inputsignal module 54 determines the ON or OFF state of the high sidetransistor 58. The high side transistor 58 receives a high voltage, suchas 600 volts, from a high voltage node 84. When the high side transistor58 is ON, an output node 62 receives the high voltage from the highvoltage node 84 through the high side transistor 58.

Referring now to FIG. 4A, a high side transistor circuit 100 thatincludes embedded signaling is shown. The high side transistor circuit100 includes a converter module 102 and a sender module 104. Theconverter module 102 includes a transformer 106 and a rectifier 108. Theconverter module 102 converts a power input signal 110 to a DC outputsignal 112. A decoding device such as a pattern recognition receivermodule 114 receives the DC output signal 112. The pattern recognitionreceiver module 114 uses the energy from the DC output signal 112 todrive the high side transistor 58.

Referring now to FIGS. 4B and 4C, the converter module 102 may includealternative circuit arrangements. For example, the converter module 102may implement an H bridge driver arrangement as shown in FIG. 4B. Theconverter module 102 may implement a center tap push pull driver asshown in FIG. 4C.

Referring now to FIGS. 4A and 5, the sender module 104 outputs the powerinput signal 110. The power input signal 110 may be a square wave signalas indicated at 120. The power input signal 110 further includes anembedded signal 122 that determines the ON or OFF status of the highside transistor 58. For example, the embedded signal 122 may be adisturbance pattern (i.e. high and/or low pulses having a longerperiod/lower frequency) that interrupts a normal pattern of the powerinput signal 110.

The pattern recognition receiver module 114 receives the embedded signal122 (via the power input signal 110) and controls the ON or OFF statusof the high side transistor 58 accordingly. The pattern recognitionreceiver module 114 includes circuitry that detects changes in thepattern of the power input signal 110. For example, the embedded signal122 may trigger the pattern recognition receiver module 114 totransition the high side transistor 58 from OFF to ON or from ON to OFF.

The embedded signal 122 may be square wave that starts low andtransitions high as indicated at 124. Alternatively, the embedded signal122 may be a square wave that starts high and transitions low asindicated at 126. In either case, the embedded signal 122 has no DCvalue to avoid saturating the transformer 106. In other words, theembedded signal 122 does not adversely affect the converter module 102as long as the pulses have equal amplitudes and the embedded signal 122does not saturate the transformer 106. When the period of the embeddedsignal 122 is below a threshold (e.g., less than three to four times aclock period of the converter module 102), the core of the transformer106 will not be saturated.

Although the embedded signal 122 as described in FIGS. 4 and 5demonstrates only two signal disturbance patterns, other signaldisturbance patterns are possible. For example, the sender module 104may embed a power on sequencing signal into the power input signal 110.In one implementation, the power on sequencing signal may direct thepattern recognition receiver module 114 and/or other components of thehigh side to begin normal operation. In another implementation, thesender module 104 may embed a shutdown signal into the power inputsignal 110 that directs the high side transistor 58 to shut down.

Referring now to FIG. 6, the high side transistor circuit 100 mayimplement reverse signaling (i.e. bi-directional communication) andincludes tri-stating the converter module 102 and/or the sender module104. For example, the high side transistor circuit 100 may include areceiver module 130 that is located on the low side of the circuit and atransmission module 132. The receiver module 130 communicates with thetransmission module 132 and the sender module 104. The transmissionmodule 132 communicates with the pattern recognition receiver module.

The pattern recognition receiver module 114 may include circuitry (notshown) for detecting various statuses of the high side of the high sidetransistor circuit 100. For example, the pattern recognition receivermodule 114 may detect statuses including, but not limited to, shortcircuit and over temperature conditions. Further, the patternrecognition receiver module may automatically detect polarity of awinding of the transformer 106. Alternatively, polarity of the windingmay be detected by sensing change in high side current during a polaritydetection search.

The converter module 102 may be temporarily disabled (e.g., tri-stated)to allow bi-directional communication (i.e. to allow the transmissionmodule 132 to transmit data). Conversely, the transmission module 132 istri-stated during normal operation. The transmission module 132communicates status information that is indicative of the detectedconditions to the receiver module 130. The transmission module 132 usesenergy stored in a capacitor 134 to operate and communicate the statusinformation. In another implementation, the receiver module 130 may beintegrated with the sender module 104 and/or the transmission module 132may be integrated with the pattern recognition receiver module 114.

The sender module 104 may generate a time allocation signal to informthe transmission module 132. For example, the sender module 104determines time allocation slots for the transmission module 132 totransmit. The transmission module 132 receives the time allocationsignal and transmits the communication information in a time allocationslot (e.g. a time slot of 3 milliseconds following the time allocationsignal).

Referring now to FIG. 7, a ballast 200 for a fluorescent lamp mayimplement the present invention. The ballast 200 includes thetransformer 106, a full or half-wave rectifier 108, an electrolyticcapacitor 202, a ballast logic module 204, and the pattern recognitionreceiver module 114. For example, the electrolytic capacitor 202 may beused to filter or smooth voltage. The ballast logic module 204 includesthe sender module 104. The rectifier 108 and the pattern recognitionreceiver module 114 may be implemented by an integrated circuit (IC)206. For example, the pattern recognition receiver module 114 may shareinput pins of the rectifier 108.

The sender module 104 generates the input power signal 110 for drivingthe high side transistor 58 as described in FIGS. 4 and 6. The ballastlogic module 204 generates a low side transistor input signal 208 fordriving a low side transistor 210. The ballast logic module 204 switchesthe transistors 58 and 210 ON and OFF to vary current and/or voltage toa fluorescent light 212 during startup and/or operation.

The fluorescent light 212 includes a sealed glass tube 214 that containsa first material such as mercury and a first inert gas such as argon,which are both generally identified at 216. The tube 214 is pressurized.Phosphor powder 218 may be coated along an inner surface of the tube214. The tube 214 includes electrodes 220A and 220B (referred tocollectively as electrodes 220) that are located at opposite ends of thetube 214. Power is supplied to the electrodes 220 according to the ON orOFF statuses of the transistors 58 and 210.

When power is supplied power to the electrodes 220, electrons migratethrough the gas 216 from one end of the tube 214 to the opposite end.Energy from the flowing electrons changes some of the mercury from aliquid to a gas. As electrons and charged atoms move through the tube214, some will collide with the gaseous mercury atoms. The collisionsexcite the atoms and cause electrons to move to a higher state. As theelectrons return to a lower energy level they release photons or light.Electrons in mercury atoms release light photons in the ultravioletwavelength range. The phosphor coating 218 absorbs the ultravioletphotons, which causes electrons in the phosphor coating 218 to jump to ahigher level. When the electrons return to a lower energy level, theyrelease photons having a wavelength corresponding to white light.

Current is output through both electrodes 220 during starting. Thecurrent flow creates a charge difference between the two electrodes 220.When the fluorescent light 212 is turned on, both electrode filamentsheat up very quickly. Electrons are emitted, which ionizes the gas 216in the tube 214. Once the gas is ionized, the voltage difference betweenthe electrodes 220 establishes an electrical arc. The flowing chargedparticles excite the mercury atoms, which triggers the illuminationprocess. As more electrons and ions flow through a particular area, theybump into more atoms, which frees up electrons and creates more chargedparticles. Resistance decreases and current increases. The ballast logicmodule 204 regulates power both during and after startup. An exemplaryfluorescent light and ballast that may implement the ballast logicmodule 204 is described in further detail in U.S. patent applicationSer. No. 11/112,808, filed on Apr. 22, 2005, which is herebyincorporated by reference in its entirety.

The ballast 200 may include a delay matching module 222. For example,the operation of the transistor 58 may be delayed during the processingof input power signal 110. For example, there may be a delay between anoutput of the sender module 104 and a response of the transistor 58. Thedelay matching module 222 adds the delay to the transistor 210. In otherwords, the delay matching module 222 offsets the response of thetransistor 210 to compensate for the delay. The ballast 200 may includea calibration circuit to adjust the delay dynamically. For example, theballast logic module 204, sender module 104, or other components of theballast 200 may determine the delay and adjust the delay matching module222 accordingly.

Referring now to FIG. 8A, an exemplary ballast logic module 204according to the present invention is shown in more detail. The ballastlogic module 204 includes a high frequency oscillator 300 and a digitalstate machine 302. For example, the sender module 104 includes the highfrequency oscillator 300 and the digital state machine 302. The digitalstage machine 302 generates the power input signal 110. In other words,the digital state machine 302 outputs the power input signal 110 at anoutput frequency according to the oscillator 300. The ballast logicmodule changes the output frequency by changing a counter value of thedigital state machine 302. To increase output frequency resolution, theballast logic module 204 may further include a digital interpolator 304.In this manner, the ballast logic module 204 may implement a morecomplex frequency scanning algorithm in the digital domain. Further, theballast logic module 204 may implement spread-spectrum technology bydithering the counter value of the digital state machine 302 around afinal average target oscillator frequency. An alternative implementationof the ballast logic module 204 is shown in FIG. 8B.

As described in FIGS. 8A and 8B, the ballast logic module 204 operatesin the digital domain to generate the disturbance pattern in the powerinput signal 110. In the digital domain, the ballast logic module 204may generate the disturbance pattern in anticipation of certain events.For example, the ballast logic module 204 may generate a square wavedisturbance signal slightly early to avoid generating extremely narrowpulses at a boundary of the normal pulses and the lower frequency (i.e.disturbance) pulses. The ballast logic module 204 is able to accuratelyadjust the lower frequency pulses so that pulse edges are preciselylocated. In other words, the normal pulses can resume immediately afterthe disturbance pulses. Further, a clock signal of the converter module102 may be derived from the digital state machine 302. In this manner,the ballast logic module 204 can synchronize pulses of the convertermodule 102 with the disturbance pulses.

The ballast module 204 may include one or more status modules 310. Forexample, the status module 310 may implement an algorithm that detectslamp end of life based on lamp ignition retries. In this manner, theballast logic module 204 can avoid damage due to overheating.Additionally, the status module 310 may implement over-voltage lampdetection by scanning startup voltage.

Those skilled in the art can now appreciate from the foregoingdescription that the broad teachings of the disclosure can beimplemented in a variety of forms. Therefore, while this disclosureincludes particular examples, the true scope of the disclosure shouldnot be so limited since other modifications will become apparent to theskilled practitioner upon a study of the drawings, the specification andthe following claims.

1. A high side transistor driver comprising: a sender module thatgenerates a power input signal; a converter module that receives thepower input signal and generates an output signal that has a highervoltage than the power input signal; and a receiver module that receivesthe output signal and the power input signal and that transitions atransistor between ON and OFF states based on the output signal and thepower input signal.
 2. The high side transistor driver of claim 1wherein the converter module includes a transformer that receives thepower input signal.
 3. The high side transistor driver of claim 2wherein the converter module includes a rectifier that communicates withthe transformer and generates the output signal.
 4. The high sidetransistor driver of claim 1 wherein the power input signal includes anembedded signal that indicates a desired state of the transistor.
 5. Thehigh side transistor of claim 4 wherein the receiver module detects theembedded signal and transitions the transistor based on the embeddedsignal.
 6. The high side transistor driver of claim 4 wherein the powerinput signal has a first frequency and a second frequency that is lowerthan the first frequency, wherein the second frequency indicates theembedded signal.
 7. The high side transistor driver of claim 1 furthercomprising a second receiver module, wherein the receiver module islocated on a high voltage side of the high side transistor driver andthe second receiver module is located on a low voltage side of the highside transistor driver.
 8. The high side transistor driver of claim 7wherein the receiver module generates a status signal and the secondreceiver module receives the status signal.
 9. The high side transistordriver of claim 8 wherein the status signal is indicative of at leastone of a short circuit condition, an over temperature condition, and apolarity of a transformer in communication with the converter module.10. The high side transistor driver of claim 1 further comprising: anoscillator that generates an oscillation signal; and a digital statemachine that generates the power input signal in response to theoscillation signal.
 11. The high side transistor driver of claim 10further comprising a digital interpolator.
 12. A ballast for afluorescent light comprising the high side transistor driver of claim 1,wherein the ballast provides current and/or voltage to the fluorescentlight based on the state of the transistor.
 13. The ballast of claim 12further comprising a ballast logic module that includes the sendermodule.
 14. The high side transistor driver of claim 4 wherein theconverter module implements a DC/DC converter and the sender modulesynchronizes the DC/DC converter with the embedded signal.
 15. The highside transistor driver of claim 1 wherein the power input signalincludes phase encoding and power delivery components.
 16. The high sidetransistor driver of claim 1 further comprising a delay matching modulethat adds a delay to a low side transistor, wherein the delaycorresponds to a delay of the high side transistor driver.
 17. The highside transistor driver of claim 8 wherein the sender module generates atime allocation signal that indicates when the second receiver module isoperable to receive the status signal.
 18. A high side transistor drivercomprising: an input module including a transformer that receives adriver input signal and generates a driver signal in response to thedriver input signal, wherein the driver input signal includes pulses; aconverter module including a transformer that receives a power inputsignal and generates an output signal that has a higher voltage than thepower input signal; and a receiver module that receives the outputsignal and the driver signal and that transitions a transistor betweenON and OFF states based on the output signal and the driver signal. 19.A high side transistor driver comprising: sending means for generating apower input signal; converting means for receiving the power inputsignal and generating an output signal that has a higher voltage thanthe power input signal; and receiving means for receiving the outputsignal and the power input signal and for transitioning a transistorbetween ON and OFF states based on the output signal and the power inputsignal.
 20. The high side transistor driver of claim 19 wherein theconverting means includes a transformer that receives the power inputsignal.
 21. The high side transistor driver of claim 20 wherein theconverting means includes a rectifier that communicates with thetransformer and generates the output signal.
 22. The high sidetransistor driver of claim 19 wherein the power input signal includes anembedded signal that indicates a desired state of the transistor. 23.The high side transistor of claim 22 wherein the receiving means detectsthe embedded signal and transitions the transistor based on the embeddedsignal.
 24. The high side transistor driver of claim 22 wherein thepower input signal has a first frequency and a second frequency that islower than the first frequency, wherein the second frequency indicatesthe embedded signal.
 25. The high side transistor driver of claim 19further comprising second receiving means for receiving a status signal,wherein the receiving means is located on a high voltage side of thehigh side transistor driver and the second receiving means is located ona low voltage side of the high side transistor driver.
 26. The high sidetransistor driver of claim 25 wherein the receiving means generates thestatus signal.
 27. The high side transistor driver of claim 26 whereinthe status signal is indicative of at least one of a short circuitcondition, an over temperature condition, and a polarity of atransformer in communication with the converting means.
 28. The highside transistor driver of claim 19 further comprising: oscillating meansfor generating an oscillation signal; and digital state machine meansfor generating the power input signal in response to the oscillationsignal.
 29. The high side transistor driver of claim 28 furthercomprising digital interpolating means for increasing an outputfrequency resolution.
 30. A ballast for a fluorescent light comprisingthe high side transistor driver of claim 19, wherein the ballastprovides current and/or voltage to the fluorescent light based on thestate of the transistor.
 31. The high side transistor driver of claim 22wherein the converter module implements a DC/DC converter and thesending means synchronizes the DC/DC converter with the embedded signal.32. The high side transistor driver of claim 19 wherein the power inputsignal includes phase encoding and power delivery components.
 33. Thehigh side transistor driver of claim 19 further comprising delaymatching means for adding a delay to a low side transistor, wherein thedelay corresponds to a delay of the high side transistor driver.
 34. Thehigh side transistor driver of claim 25 wherein the sending meansgenerates a time allocation signal that indicates when the secondreceiving means is operable to receive the status signal.
 35. A highside transistor driver comprising: converting means including atransformer for receiving a power input signal and generating an outputsignal that has a higher voltage than the power input signal; inputmeans including a transformer for receiving a driver input signal andgenerating a driver signal in response to the driver input signal,wherein the driver input signal includes pulses; and receiving means forreceiving the output signal and the driver signal and for transitioninga transistor between ON and OFF states based on the output signal andthe driver signal.
 36. A method for driving a high side transistor in acircuit, comprising: generating a power input signal; receiving thepower input signal and generating an output signal that has a highervoltage than the power input signal at a first module; receiving theoutput signal and the power input signal at a second module; andtransitioning a transistor between ON and OFF states based on the outputsignal and the power input signal.
 37. The method of claim 36 whereinreceiving the power input signal at the first module includes receivingthe power input signal at a transformer.
 38. The method of claim 37further comprising rectifying the power input signal at the firstmodule.
 39. The method of claim 36 wherein the power input signalincludes an embedded signal that indicates a desired state of thetransistor.
 40. The method of claim 39 further comprising detecting theembedded signal and transitioning the transistor based on the embeddedsignal.
 41. The method of claim 39 wherein the power input signal has afirst frequency and a second frequency that is lower than the firstfrequency, wherein the second frequency indicates the embedded signal.42. The method of claim 39 further comprising: generating a statussignal at the second module; and receiving the status signal at a thirdmodule, wherein the second module is located on a high voltage side ofthe circuit and the third module is located on a low voltage side of thecircuit.
 43. The method of claim 42 wherein the status signal isindicative of at least one of a short circuit condition, an overtemperature condition, and a polarity of a transformer in communicationwith the first module.
 44. The method of claim 36 further comprising:generates an oscillation signal; and generating the power input signalat a digital state machine in response to the oscillation signal. 45.The method of claim 36 further comprising providing current and/orvoltage to a fluorescent light based on the state of the transistor. 46.The method of claim 36 wherein the first module includes a DC/DCconverter and further comprising synchronizing the DC/DC converter withthe embedded signal.
 47. The method of claim 36 further comprisingadding a delay to a low side transistor, wherein the delay correspondsto a delay of the high side transistor.
 48. The method of claim 42further comprising generating a time allocation signal that indicateswhen the third module is operable to receive the status signal.